Who is the worst president of United States ?

[Joe Biden 2020]

1) Warren Harding
2) James Buchanan
3) Ulysses Grant
4) Andrew Johnson
5) Jimmy Carter

Bush doesn't even make the bottom 10 in my opinion.  He's in the bottom 20, but not bottom 10 or even bottom 5.

Harding didn't do very well cleaning up from WWI.
Buchanan comes very close to Harding, but just a hair better.
Grant was just a pure drunkard during the War and was horrible during Reconstruction in not starting to integrate the South
Johnson was the first President to be impeached
Carter was clearly a better ex-president than president.  Our problems with Saddam Hussein and with Iran started with him.  He was the first full post-Vietnam administration (Gerald Ford officially ended it in 1975.)